Abstract

Net type net blotch (NTNB) is a prevalent disease in Australia, causing significant losses in barley yield and quality. Its impact can be reduced with the identification and utilisation of effective sources of resistance. Sixty-nine cultivated barley lines were screened as seedlings against 9 isolates of Pyrenophora teres f. teres from Australia, and in the field in Western Australia. Resistance expressed in seedlings was frequently expressed in adult plants in the field, indicating that these sources are potentially useful for resistance breeding. Of these lines, 24 with the best overall resistance were identified, which could be used against virulence diversity present in P. teres f. teres in Australia.

As a prelude to the evaluation of established mapping populations in the Australian Barley Molecular Marker Program, 42 parental lines were screened against a range of Australian isolates of P. teres f. teres. Variation in net blotch responses was observed among parents of the mapping populations. Ten principal mapping populations appear to provide opportunities to map resistances and identify molecular markers linked to NTNB resistance genes effective against Australian pathotypes.